Hide any typographic block that is empty.

empty-blocks.css

p:empty,
h1:empty,
h2:empty,
h3:empty,
h4:empty,
h5:empty,
h6:empty,
ul:empty,
ol:empty,
dl:empty,
li:empty,
dt:empty,
dd:empty,
blockquote:empty {
	/* Hide any typographic block that is empty. This is a bit
	   contraversial, but helps correct style errors in blocks
	   of user input where the HTML has ended up being dodgy -
	   perhaps thanks to a CMS editor, for example. */
	display: none;
}